[PATCH 3.16.y-ckt 100/185] ext4: don't retry file block mapping on bigalloc fs with non-extent file

[Luis Henriques]

3.16.7-ckt15 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: "Darrick J. Wong" <darrick.wong at oracle.com>

commit 292db1bc6c105d86111e858859456bcb11f90f91 upstream.

ext4 isn't willing to map clusters to a non-extent file.  Don't signal
this with an out of space error, since the FS will retry the
allocation (which didn't fail) forever.  Instead, return EUCLEAN so
that the operation will fail immediately all the way back to userspace.

(The fix is either to run e2fsck -E bmap2extent, or to chattr +e the file.)

Signed-off-by: Darrick J. Wong <darrick.wong at oracle.com>
Signed-off-by: Theodore Ts'o <tytso at mit.edu>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 fs/ext4/indirect.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/ext4/indirect.c b/fs/ext4/indirect.c
index 944c49dd83e3..0c9ed67fe055 100644
--- a/fs/ext4/indirect.c
+++ b/fs/ext4/indirect.c
@@ -576,7 +576,7 @@ int ext4_ind_map_blocks(handle_t *handle, struct inode *inode,
 				       EXT4_FEATURE_RO_COMPAT_BIGALLOC)) {
 		EXT4_ERROR_INODE(inode, "Can't allocate blocks for "
 				 "non-extent mapped inodes with bigalloc");
-		return -ENOSPC;
+		return -EUCLEAN;
 	}
 
 	goal = ext4_find_goal(inode, map->m_lblk, partial);